[kernel-hardening] Re: [PATCH v3 1/2] modules:capabilities: automatic module loading restriction
From: Ben Hutchings <hidden>
Date: 2017-04-20 15:02:44
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On Thu, 2017-04-20 at 14:44 +0200, Djalal Harouni wrote:
quoted
On Thu, Apr 20, 2017 at 4:22 AM, Ben Hutchings [off-list ref] wrote: On Thu, 2017-04-20 at 00:20 +0200, Djalal Harouni wrote: [...]quoted
+modules_autoload: + +A sysctl to control if modules auto-load feature is allowed or not. +This sysctl complements "modules_disabled" which is for all module +operations where this flag applies only to automatic module loading. +Automatic module loading happens when programs request a kernel feature +that is implemented by an unloaded module, the kernel automatically +runs the program pointed by "modprobe" sysctl in order to load the +corresponding module. + +When modules_autoload is set to (0), the default, there are no +restrictions. + +When modules_autoload is set to (1), processes must have CAP_SYS_MODULE +to be able to trigger a module auto-load operation, or CAP_NET_ADMIN +for modules with a 'netdev-%s' alias. + +When modules_autoload is set to (2), automatic module loading is +disabled for all. Once set, this value can not be changed.I would expect a parameter 'modules_autoload' to be a boolean, so this behaviour would be surprising. What is the point of mode 2???Why would someone want to set modules_disabled=0 and modules_autoload=2?modules_disabled is too restrictive and once set it can't be changed, maybe that's why not all users use it. With modules_disabled=0 and modules_autoload=2
[...] Hmm, OK. How about naming this modules_autoload_mode, then, so that it's obviously not a boolean? Ben. -- Ben Hutchings It is easier to change the specification to fit the program than vice versa. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: This is a digitally signed message part URL: <http://kernsec.org/pipermail/linux-security-module-archive/attachments/20170420/9bb425aa/attachment.sig>